Leg : 17 Top/Bottom Interval(mm): / Describer: Bass, M.
Hole: 171 Top of Core Depth(m) : 325.00 Rock Type: IGNEOUS
Core: 26 Sample Midpoint(m) : 329.60 Sect/Pc #: CC/
ROCK = PLAG SPARSELY MICROPHYRIC BASALT
SOURCE IS IR,SEE P. 498;
Texture: FINE- TO MEDIUM-GRAINED,PHRYRIC*
Phenocrysts- PLAGIOCLASE ( 1.2%)
OLIVINE
Size(mm): 0.6X0.45 Morphology: PSEUDOMORPHS
Groundmass - OPAQUE MINERALS ( TR%)
Morphology: EQUANT
MIN SIZE=0.02,MAX SIZE=0.03,REPLACING OL;
PLAGIOCLASE ( 32.5%)
Size(mm): 0.2X0.03
GROUNDMASS ( 42.7%)
DENSE
INCLUDES MOST OP.MINS IN ROCK,MAIN COMPONENTS ARE
PROBABLY MONT+PYX+OP.MINS,MODAL ANALYSIS*
Alteration - MONTMORILLONITE ( 9.7%)
Location: PSEUDOMORPHS Replacing: OL
ENCLOSE TRACE AMOUNTS OF EQUANT,EUHEDRAL OP.MINS,
THE PRESENCE OF WHICH IS ONE OF THE BEST WAYS TO
DISTINGUISH MONT AFTER OL FROM MONT AMYGDULES;
CALCITE ( 0.5%)
Location: PSEUDOMORPHS Replacing: OL
CALCITE ( 0.6%)
Location: VEINS,
Location: AMYGDULES
THIN-SECTION CUT TO AVOID LARGE CONENTRATION OF
VEINS AND PATCHES*
Vesicles -
Size(mm): 0.15
Percent: 12.7
Filling: MONT
Leg : 17 Top/Bottom Interval(mm): 750/ 860 Describer: Bass, M.
Hole: 171 Top of Core Depth(m) : 334.00 Rock Type: IGNEOUS
Core: 27 Sample Midpoint(m) : 336.31 Sect/Pc #: 2/
ROCK = OL-PLAG MICROPHYRIC BASALT
SOURCE IS IR, SEE PP.499-500,HIGHLY ALTERED;
Texture: FINE-GRAINED,PHYRIC*
Phenocrysts- OLIVINE
Morphology: PSEUDOMORPHS
MICROPHENOS;
PLAGIOCLASE ( 1.9%)
Size(mm): 0.45X0.10
Groundmass - PLAGIOCLASE ( 11.5%)
Size(mm): 0.17X0.03
GROUNDMASS ( 40.7%)
NO VISIBLE PYX BUT IT APPEARS IN TOTAL ROCK X-RAY
PATTERN,MONT AND OP.MINS APPEAR TO BE PRESENT IN
ROUGHLY EQUAL AMOUNTS AND THE OP.MINS INCLUDE
ILMENITE;
OPAQUE MINERALS
INCLUSIONS;
CHROME SPINEL
INCLUSIONS,MODAL ANALYSIS*
Alteration - MONTMORILLONITE ( 7.7%)
Location: PSEUDOMORPHS Replacing: OL
CALCITE ( 0.1%)
Location: PSEUDOMORPHS Replacing: OL
MONTMORILLONITE ( 1.4%)
Location: MICROPHENOS Replacing: PLAG
MONTMORILLONITE
Location: GROUNDMASS Replacing: PLAG
MONTMORILLONITE ( 26.3%)
Location: OVOIDS,
Location: PATCHES
CALCITE ( 0.1%)
IN MONT OVOIDS AND PATCHES;
PYRITE
INCLUSION IN MONT OVOIDS AND PATCHES
OF DIAGENETIC ORIGIN*
Leg : 17 Top/Bottom Interval(mm): 820/ 860 Describer: Bass, M.
Hole: 171 Top of Core Depth(m) : 334.00 Rock Type: IGNEOUS
Core: 27 Sample Midpoint(m) : 337.84 Sect/Pc #: 3/
ROCK = OL-PLAG-PYX MICROPHYRIC BASALT
SOURCE IS IR,SEE P.501,HIGHLY ALTERED;
Texture: MEDIUM TO COARSE-GRAINED,INTERSERTAL TO
SUBOPHITIC,PHYRIC*
Phenocrysts- OLIVINE ( 5.0%)
Morphology: PSEUDOMORPHS
PLAGIOCLASE ( 25.1%)
Size(mm): 0.25X0.03
GROUNDMASS AND MICROPHENOS,MIN SIZE=0.1X0.02,
MAX SIZE= 0.85X0.1;
PYROXENE ( 3.6%)
Morphology: INTERSERTAL,SUBOPHITIC
REMNANTS,MIN SIZE=0.15X0.1,MAX SIZE=0.45X0.35*
Groundmass - OPAQUE MINERALS ( 10.9%)
Morphology: ELONGATE,EQUANT
ELONGATE: MIN-0.04X0.004,MAX=0.08X0.004,
EQUANT: MIN=0.004,MAX=0.01,EQUANT INCL.IN OLIVINE:
MIN=0.008,MAX=0.025,MODAL ANALYSIS*
Alteration - MONTMORILLONITE ( 35.0%)
INTERSERTAL,PROBABLY REPLACES PYX AND INTERSERTAL
RESIDUUM;
MONTMORILLONITE ( 19.2%)
Location: PATCHES,
Location: OVOIDS
LOCALLY SO ABUNDANT THAT LITTLE "GROUNDMASS" (PYX+OP.MINS+MONT) IS EVIDENT;
CALCITE ( 1.2%)
Location: PATCHES
Location: OVOIDS
PYRITE ( TR%)
IN MONT AND CALCITE PATCHES AND OVOIDS*
Leg : 17 Top/Bottom Interval(mm): / Describer: Bass, M.
Hole: 171 Top of Core Depth(m) : 464.00 Rock Type: IGNEOUS
Core: 33 Sample Midpoint(m) : 464.10 Sect/Pc #: CC/
ROCK = OL MICROPHYRIC BASALT
SOURCE IS IR,SEE PP. 502-503;
Texture: FINE-GRAINED,PHYRIC,CHILLED,BUT OUTERMOST
SELVAGE NOT PRESENT*
Phenocrysts- OLIVINE ( 9.8%)
Size(mm): 0.6X0.45 Morphology: PSEUDOMORPHS
MONT PSEUDOMORPHS ,OFTEN GLOMERATIC,ORANGE-BROWN
IDDINGS ALONG RIMS AND CRACKS*
Groundmass - PLAGIOCLASE ( 29.5%)
Size(mm): 0.25X0.03
CENTERS OF SOME GRAINS ALTERED TO DUSTY BROWN
MONT;
OPAQUE MINERALS ( 0.1%)
Size(mm): 0.25X0.25 Morphology: SKELETAL PLATY GRAINS
INCLUSIONS IN OL;
OPAQUE MINERALS ( 13.6%)
Size(mm): 0.1X0.10 Morphology: SKELETAL PLATY GRAINS
PYROXENE ( 10.4%)
Size(mm): 0.08X0.05 Morphology: INTERGRANULAR,SUBOPHITIC
MOST PYX PROBABLY ALTERED TO MONT BUT NO DIRECT
EVIDENCE;
OLIVINE ( 11.9%)
Size(mm): 0.05X0.04 Morphology: PSEUDOMORPHS
COMPLETELY OXIDIZED TO ORANGE-BROWN IDDINGS,
MODAL ANALYSIS*
Alteration - MONTMORILLONITE ( 24.7%)
Location: GROUNDMASS
LIGHT GRAYISH BROWN INTERSERTAL,IDENTICAL TO MONT
OF THE PSEUDOMORPHS AFTER OL;
CHLORITE ( TR%)
Location: VEINS,RIMS
Vesicles -
Size(mm): TO 8X3
Filling: MONT
|
